ANTHROPOLOGIST PREDICTS MAJOR THREAT TO SPECIES WITHIN
50 YEARS

COLUMBUS, Ohio – If the world’s human population
continues to rise at its current rate, the planet will increase the numbers
of threatened species at least 7 percent worldwide in the next 20 years
and twice that many by the year 2050.

In a recent model of the impact human population growth
has on biological diversity, Ohio State University anthropologist Jeffrey
McKee and his colleagues warn that the United States alone will add
at least 10 additional species to the “threatened” list within
50 years.

“If other species
follow the same pattern as the mammals and birds in our study, then
we are facing a serious threat to global biodiversity associated
with our growing human population.”

The prediction, carried in a paper published in the journal
Biological Conservation,
arose from an effort by McKee to separate the effects of the numbers of
humans from questions about how they use – or abuse – the
environment.

McKee, an associate professor of both anthropology
and of evolution,
ecology and organismal biology at the university, was seeking a direct
correlation between population growth and the number of threatened species.
To do so, he had to balance the size of each country against the number
of people living within its borders in order to develop an accurate population
density.

“We knew that there are a number of natural components
(that can affect species vulnerability),” he said. “We wanted
to put all of the countries in the study on a level playing field in terms
of their particular environments and the number of species present.”

Once they combined the natural factors together with the
human factors and did the tabulations, McKee says the result was an 88
percent predictability of how many species would be threatened if human
population continued to grow.

The remaining 12 percent, he says, is explainable using
other variables, such as the number of endemic species in a specific country
as well as differences in patterns of human behavior. The greater the
diversity, he said, the more likely his estimate could be wrong because
of the greater number of species still unknown to science.

McKee’s prediction that the United States would face
10 additional threatened species in the next half-century may seem minimal,
he said, but it isn’t.

“The loss of an additional 10 species of mammals
and birds doesn’t sound like a lot but it really is,” he said.
“Remember, it takes hundreds of thousands of years for a new species
to arise. We’re saying that it may only take 50 years for 10 of
them to reach the brink of extinction.”

McKee emphasized that this predicted additional 10 species
at risk does not include the current rate of disappearing species the
world now faces.

“In our study, we only looked at species of mammals
and birds,” he said. “We didn’t include the countless
species of insects and other life forms, many of which are relatively
unknown, in this analysis.”

McKee sees the loss of these mammals and birds as a kind
of “canary in a coal mine” phenomenon, a warning of the impact
on the environment.

“We have no way of knowing before it is lost if one
particular animal is a ‘keystone’ species – one upon
which countless others depend,” he said.

To reach his conclusions, McKee started with data on 230
nations. He excluded island nations and those whose small size forced
an unusual population density. Other nations, such as the former Soviet
block, were excluded for lack of precise data. In the end, he used a list
of 114 countries worldwide.

His study pointed to the Congo as having the worst future
– an estimated addition of 26 threatened species by the year 2050,
an increase of 39.8 percent. At least 100 of the 114 nations covered in
the study showed a possible increase in the number of threatened species.
Another 10 nations should have a decrease in the number of threatened
species by 2050, because of their individual declines in human population,
he said.

“The density of people is a key factor in species
threats,” he says, “depending upon the ecological nature of
a nation and the number of species ‘available’ for the threat
of extinction.

“If other species follow the same pattern as the
mammals and birds in our study, then we are facing a serious threat to
global biodiversity associated with our growing human population.”